Veenstra, RL 2015, 'A methodology for predicting dilution of cemented paste backfill', in Y Potvin (ed.), Design Methods 2015: Proceedings of the International Seminar on Design Methods in Underground Mining, Australian Centre for Geomechanics, Perth, pp. 527-539, https://doi.org/10.36487/ACG_rep/1511_33_Veenstra (https://papers.acg.uwa.edu.au/p/1511_33_Veenstra/) Abstract: This paper presents results from a numerical modelling exercise that looks at predicting the amount of backfill dilution expected from vertically exposed cemented paste backfill (CPB). The paper initially presents the process by which model input parameters were determined from laboratory testing and then shows how the model and laboratory results compare. The paper then presents the methodology for determining when the vertically exposed backfill mass fails and for calculating the amount of backfill dilution from this failure. A series of models were run for simple rectangular stopes for easy comparison to existing analytical exposure models. Finally, a case study was conducted by comparing the results of the methodology to cavity monitoring survey (CMS) data from an underground stope.